In anatomy and zoology: Of or pertaining to a vesicle; of the form or nature of a vesicle; cystic; bladdery.Having a vesicle; vesiculate; full of or consisting of vesicles, especially when they are small and numerous; areolar; cellular: as, the vesicular tissue of the lungs; a vesicular polyp.In botany, pertaining to or consisting of vesicles; appearing as if composed of small bladders; bladdery.In geology, the epithet applied to rocks having a cellular structure, the cavities being rather large and well rounded, but not very abundant.