cor·pus·cle 
(kôrpə-səl, -pŭs′əl)
(kôrpə-səl, -pŭs′əl)n.
1.
a. An unattached body cell, such as a blood or lymph cell.
b. A rounded globular mass of cells, such as the pressure receptor on certain nerve endings.
2. A discrete particle, such as a photon or an electron.
3. A minute globular particle.
[Latin corpusculum, diminutive of corpus, body; see kwrep- in the Appendix of Indo-European roots.]
cor·puscu·lar (kôr-pŭskyə-lər) adj.