reserve
v.
mid-14c., from Old French reserver "set aside, withhold" (12c.) and directly from Latin reservare "keep back, save up; retain, preserve," from re- "back" (see re-) + servare "to keep, save, preserve, protect" (see observe). Meaning "to book" is from 1935. Related: Reserved; reserving.
n.
"something stored up," 1610s, from reserve, v. or from French réserve, a Middle French back-formation from reserver. Meaning "self-imposed restraint on freedom of words or actions; habit of keeping back the feelings" is from 1650s.
〔李〕[re-=back 回；serv=to keep 保持；-e→] v. keep back；hold back for later use 储备，保留
〔李〕[re-;serv;-e] v.保留； 预定，预约 ←serv (L servare)=to keep or protect 保护，保存