Bubbuḷaka = bubbuḷa, viz. 1. a bubble Dhp-a III 166; Miln 118. 2. the iris of the eye Thig 395 (cf. Morris, in JPTS 1884, 89, but according to Thig-a 259 the reading pubbaḷhaka is to be preferred.)
(nt, nt, dimin of bubbuḷa) little bubble Construction: bubbuḷa + ka