noun.
The upper angle between a lateral organ, such as a leaf, and the stem that bears it.
The Century Dictionary and Cyclopedia
noun.
The armpit, or axilla (which see).
noun.
In botany, the angle formed between the upper side of a leaf and the stem or branch to which it is attached; in cryptogams, the angle formed by the branching of a frond.
the GNU version of the Collaborative International Dictionary of English
noun.
The angle or point of divergence between the upper side of a branch, leaf, or petiole, and the stem or branch from which it springs.
noun.
The angle or point of divergence between the upper side of a branch, leaf, or petiole, and the stem or branch from which it springs.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
the upper angle between an axis and an offshoot such as a branch or leafstalk
Word Usage
"In the first place, a slit is made on each side and above and below a leaf which has a healthy bud in its axil, that is, just between the foot-stalk of the leaf and the branch on which it grows."