mono- or mon-
1. One; single; alone: monomorphic.
2. Containing a single atom, radical, or group: monobasic.
3. Monomolecular; monatomic: monolayer.
[Middle English, from Old French, from Latin, from Greek, from monos, single, alone; see men-4 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.