I encountered a derivative of this in a rhetoric site, in a
discussion of expletives - "accostives". I searched for it,]
could not find a dictionary defintion. So I looked up
"accost" and got some surpises, particularly the etymology.
Webster's 1913 Dictionary

Definition: \Ac*cost"\ (#; 115), v. t. [imp. & p. p. {Accosted}; p.
pr. & vb. n. {Accosting}.] [F. accoster, LL. accostare to
bring side by side; L. ad + costa rib, side. See {Coast}, and
cf. {Accoast}.]
1. To join side to side; to border; hence, to sail along the
coast or side of. [Obs.] ``So much [of Lapland] as accosts
the sea.'' --Fuller.

2. To approach; to make up to. [Archaic] --Shak.

3. To speak to first; to address; to greet. ``Him, Satan thus
accosts.'' --Milton.

\Ac*cost"\, v. i.
To adjoin; to lie alongside. [Obs.] ``The shores which to the
sea accost.'' --Spenser.

\Ac*cost"\, n.
Address; greeting. [R.] --J. Morley.

I have seen "accost" used only to mean to speak to someone,
especially someone not known to you. I think it is also sometimes a legal term, similary to "soliciting", as part of a charge against prostitutes, or their "johns". I had no idea that ribs were involved!

An "accostive" then might be similar to a "salutation" (which doesn't alway mean wishing someone good health).