[ sʌb'tɛnd ]
■ verb
1》 Geometry (of a line, arc, etc.) form (an angle) at a particular point when straight lines from its extremities meet.
↘(of an angle or chord) have bounding lines or points that meet or coincide with those of (a line or arc).
2》 Botany (of a bract) extend under (a flower) so as to support or enfold it.
Origin
C16: from L. ~ere , from sub- 'under' + tendere 'stretch'.