Definitions of HOKUM are legion but generally refer to any of the following:

1. a) Flattery.
   b) To hoax.
   c) Anything designed to make a melodramatic or sentimental appeal.
   d) Bunkum.
   e) Lie: “All that is hokum, I want the truth”.
   f) Tall tale.
   g) Theatrically: obvious or familiar elements of low comedy, melodrama, sentimentality, or the like, designed to appeal strongly to an unsophisticated audience.

According to various dictionaries of slang, the word HOKUM is probably derived from a combination of hocus–pocus [which, itself, means nonsense] & bunkum. The most common meaning, therefore, is simply ‘nonsense’.
By the end of the 1920’s, however, it had become far more commonly associated with sexual innuendo…

Edited from Wikipedia, the free encyclopedia: In this context the article that follows specifically refers to a particular song type of American blues music.

Hokum is a particular song type of American blues. Hokum songs are humorous songs that use extended analogies or euphemistic terms to make sexual innuendos. The song type goes back to the earliest blues recordings and is still occasionally found in modern American blues and blues-rock.

In a general sense, hokum was a style of comedic farce, spoken, sung and spoofed, while masked in both risqué innuendo and “tomfoolery”. It is one of the many legacies and techniques of 19th century low comedy.  Like so Hokum was stagecraft, gags and routines for embracing farce. It was so broad in its meaning that there was no mistaking its ludicrousness. Hokum also encompassed dances like the cakewalk and the buzzard lope in skits (sketches) that unfolded through spoken narrative and song. W.C. Handy, himself a veteran of a minstrel troupe, remarked that, “Our hokum hooked ’em,” meaning that the low comedy snared an audience that stuck around to hear the music. In the days before ragtime, jazz or even hillbilly music or the blues were clearly identified as specific genres, hokum was a component of “all around” performing, entertainment that seamlessly mixed monologues, dialogues, dances, music, and humor.

Amongst the early performers of hokum who surfaced among the Memphis, Tennessee jug bands heard in Beale Street’s saloons and bordellos were the light-hearted and humorous jug bands such as Will Shade’s Memphis Jug Band and Gus Cannon’s Jug Stompers who played good time, upbeat music on assorted instruments, such as spoons, washboards, fiddles, triangles, harmonicas, and banjos, all anchored by bass notes blown across the mouth of an empty jug. Their blues was rife with popular influences of the time, and had none of the grit and plaintive “purity” of the nearby Delta blues. Cannon’s classic composition Walk Right In, originally recorded for Victor in 1930, resurfaced as a Number One hit 33 years later, when the Rooftop Singers recorded it during the Folk Revival in New York’s Greenwich Village, and a jug band boom ensued once more.

An example of hokum lyrics is seen in these first two verses from the song Banana In Your Fruit Basket by Bo Carter (Chatmon), who recorded it in 1931:

I got a brand new skillet, I got a brand new lead,
All I need is a little woman, just to burn my bread,
Then I’m tellin’ you baby, I sure ain’t gonna deny it,
Let me put my banana in your fruit basket, then I’ll be satisfied.

Now, I got the washboard, my baby got the tub,
We gonna put ’em together, gonna rub, rub, rub,
Then I’m tellin’ you baby, I sure ain’t gonna deny it,
Let me put my banana in your fruit basket, then I’ll be satisfied.

Hokum blues lyrics specifically poked fun at all manner of sexual practices, preferences, and eroticized domestic arrangements. Compositions such as Banana In Your Fruit Basket, written by Bo Carter of the Mississippi Sheiks, used thinly veiled allusions, which typically employed food and animals as metaphors in a lusty manner worthy of Chaucer. The hilariously sexy lyric content usually steered clear of subtlety. Another master of the genre was the bottleneck guitarist Tampa Red, who recorded It’s Tight Like That for the Vocalion label in 1928, accompanied by Thomas A. Dorsey on piano. The song was so popular that the two became the core of the recording group, the Famous Hokum Boys. Both had previously performed in the band that accompanied Ma Rainey when she sang the vaudeville circuit. The Hokum Boys recorded over 60 songs by 1932, most of them written by Dorsey, who later put the blues aside and became the founding father of black gospel singing. Dorsey later characterized his hokum legacy as “deep moanin’, low-down blues…!”

References:
BEALE, Paul (ed.)
(1989) Partridge’s Concise Dictionary of Slang and Unconventional English, from the work of Eric Partridge. Macmillan Publishing Company, New York.
GREEN, Jonathon.
(1986) The Penguin Slang Thesaurus. Penguin Books, London, I>etc (Second edition, 1999)
LIGHTER, J.E. (ed.)
(1997) Random House Historical Dictionary of American Slang. Volume 2, H–O. Random House, New York.
SPEARS, Richard A.
(1989) NTC’s Dictionary of American Slang and Colloquial Expressions. National Textbook Company, Lincolnwood.