in addition to

ôštâp "hurry, haste," ôštâftan "to hurry, hasten," from *abi.stap-, from abi- " to; in addition to; against" + *stap- "to oppress," Arm. (loanword) štap

There have been many attempts to qualify the ar- verbal root of Old Iranian *arya- (with short-a, found in Old Persian as ariya-, and Avestan as airiia-