mola (n.1) Look up mola at Dictionary.com
type of fish, 1670s, from Latin mola, literally "millstone" (see molar). So called because of the fish's shape and rough skin.
mola (n.2) Look up mola at Dictionary.com
"false conception," c.1600, from Latin mola "false conception," from earlier sense "salt cake;" literally "millstone" (see molar).