1) Spore 
Tetraspores are red algae spores produced by the tetrasporophytic (diploid) phase in the life history of the Rhodophyta as a result of meiosis. The name is derived from the 4 spores that form after this meiosis, the division is of three kinds: cruciate, zonate and tetrahedral. ...
• (n.) A nonsexual spore, one of a group of four regularly occurring in red seaweeds.
(from the article `algae`) The red algae, as exemplified by Polysiphonia, have some of the most complex life cycles known for living organisms. Following meiosis, four haploid ...
Tet'ra·spore noun [ Tetra- + spore .] (Botany) A nonsexual spore, one of a group of four regularly occurring in red seaweeds. -- 
[n] - one of the four asexual spores produced within a sporangium
noun one of the four asexual spores produced within a sporangium