illā adv.
ablf. of ille, sc. viā, in that way, in that direction, there : Oceanum illā tentavimus, Ta.: revertebar illā, quā, etc., O.
illa, adv., v. ille fin. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
illa- in compounds with in; see inla-. ...
An Elementary Latin Dictionary