adj. Closely united by the coalescence of contiguous faces.
the GNU version of the Collaborative International Dictionary of English
adj. Closely united by the coalescence, or sticking together, of contiguous faces, as in the case of the cotyledons of the live-oak acorn.
The Century Dictionary and Cyclopedia
Soldered together; consolidated as if soldered together; specifically, in botany, closely adherent, so as to be separated with difficulty, as the cotyledons of the horse-chestnut.