In French, « partir » means "to (de)part". So what semantic notions underlie French's « re » + « partir » with its 2020 AD English meaning of [riposting](https://cnrtl.fr/definition/repartir) »? I see no semantic relation between (de)parting and replying, probably because I know nothing about fencing. [repartee (n.)](https://www.etymonline.com/word/repartee#etymonline_v_12818 "Origin and meaning of repartee")
> 1640s, "quick remark," from French *repartie* "an answering blow or thrust" (originally a fencing term), noun use of fem. past participle of Old French *repartir* "to reply promptly, start out again,"
from *re-* "back" (see [re-](https://www.etymonline.com/word/re-) + partir "to divide, separate, set out,"
from Latin *partiri* "to share, part, distribute, divide,"
from *pars* "a part, piece, a share" (from PIE root [*pere-](https://www.etymonline.com/word/*pere-) (2) "to grant, allot").
> In 17c. often spelled reparty (see [-ee](https://www.etymonline.com/word/-ee)). Meaning "a series of sharp rejoinders exchanged" is from 1680s.
