n. & adj.
--n. any marine animal of the subphylum Urochordata having a rubbery or hard outer coat, including sea squirts.
--adj.
1. Zool. of or relating to this subphylum.
2 a Zool. enclosed in a tunic. b Bot. having concentric layers.
Etymology: L tunicatus past part. of tunicare clothe with a tunic (as TUNICA)