tì
take the place of, stand in for
Depicts two people (夫) standing side-by-side, one person higher and one person lower. Represents one person taking the place of another. The 曰 component was added at the bottom to distinguish from 並, which also depicts two people standing side-by-side.
Evolution

Oracle script
(~1250-1000 BC)
Bronze script
Late Warring States (~250 BC)
Seal script
Shuowen (~100 AD)
Clerical script
Western Jin dynasty (266-316 AD)Regular script
ModernDefinitions
tì
change, replace, substitute for; to substitute for; to take the place of; to replace; for; on behalf of; to stand in for
Component uses
Sound component in 1 character (0 verified)
Sources
李学勤《字源》p.922-923