Wiktionary
amastigote
n. (context biology English) Any cell (or unicellular organism) that does not have any flagella or cilia
Wikipedia
Amastigote
An amastigote is a protist cell that does not have visible external flagella or cilia. The term is used mainly to describe a certain phase in the life-cycle of trypanosome protozoans. It is also called the leishmanial stage, since in Leishmania it is the form the parasite takes in the vertebrate host, but occurs in all trypanosome genera.