(now chiefly biology, geology) An act of folding. / (now chiefly biology, geology) A fold or pleat.

To find out definitely; to discover or establish. / (obsolete) To make (someone) certain or confident about something; to inform. / (archaic) To establish, to prove. / (archaic) To ensure or effect.

The state of being convertible; convertibility.

Impossible to shift; immovable.