- A tube or a canal.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for tubus
Tubus: a term used to designate the corneous base of a ligula: the sheath of the tongue.Explanation of Terms Used in Entomology
John. B. Smith