extrinsic factor n.
See vitamin B12.
- Extrinsic incubation period
extrinsic incubation period n. The interval between the acquisition of an infectious agent by a vector and the vector’s ability to transmit the agent to other susceptible vertebrate hosts.
- Extrinsic sphincter
extrinsic sphincter n. A sphincter formed by circular muscular fibers extraneous to the organ.
1. variant of (used to contrast with intro-, ): extrovert. word-forming element meaning “outwards,” a variant of extra- by influence of intro-. extro- pref. Variant of extra-.
noun, adjective an advocate of the theory that cultural and technological development will expand indefinitely and in an orderly progressive manner throughout the universe