"friend or partner" ... used by Juvenile from Cash Money Records

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

also abbreviated to wo'
It is derived from wardie, someone from one of New Orleans' wards, 9th ward, 7th ward, etc.

friend or good comrad; popular in the southern urban communites and prison. (originally wardie, evolved in late 90's)

friend, road dog, roadie, homeboy, homie. Specific to New Orleans and immediate environs, of uncertain origin. Possibly derived from the New Orleans customary greeting of "Whoa, now!" Others theorize that the term may be a corruption of "wardie", i. e. someone who comes from the same ward or neighborhood of New Orleans. Possibly spread to other regions of the country through rap music.

real talk and my dougie.

Orginating from prison culture in the south, "Warden", was shorten to "war-day". Used to signify friend as well show respect.