base, bottom, minimum
Any basal structure or part
Basic, elementary; relating to, or forming, the base, or point of origin.
In a phylogenetic tree, being a group, or member of a group, which diverged earlier. The earliest clade to branch in a larger clade.
Associated with the base of an organism or structure.
Of a minimal level that is necessary for maintaining the health or life of an organism.
The base after home plate in a counter-clockwise path around a baseball infield.
Completion of the first phase of an activity.
Kissing, regarded as the first phase of a sexual relationship.
The betting spot located immediately to the left of the dealer, which is first to receive cards and first to act.