Appositive or as adjective, as urchin article, urchin bitch, urchin deity, urchin messenger, urchin prince.

In names of plants and animals that are naturally smaller than others of a related or (supposedly) similar kind.

Of or relating to animalcules; of the nature of an animalcule; caused by animalcules. Now historical.

= animalcular, adj. 1.