#1 base v. [establish, ground, found] use as a basis for; found on; "base a claim on some observation". wn
#2 base n. [base of operations] installation from which a military force initiates operations; "the attack wiped out our forward bases". wn
#3 base n. [foundation, fundament, foot, groundwork, substructure, understructure] lowest support of a structure; "it was built on a base of solid rock"; "he stood at the foot of the tower". wn
#4 base n. [bag] a place that the runner must touch before scoring; "he scrambled to get back to the bag". wn
#5 base n. the bottom or lowest part; "the base of the mountain". wn
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