"the first milk secreted in the breasts after childbirth," 1570s, from Latin colostrum "first milk from an animal," earlier colustra, a word of unknown etymology.
fem. proper name, from French Irène, from Latin Irene, from Greek Eirēnē, literally "peace, time of peace," a word of unknown etymology.
1690s, Modern Latin, from Greek thrombos "lump, piece, clot of blood, curd of milk," a word of uncertain etymology.
"a decorative form representing a living object," 1895 (A.C. Haddon), from bio- "life" + -morph "form," a word of uncertain etymology. Related: Biomorphic.