Origin: Germanic Old English prefix
Forearm has 4 different meanings across 2 categories:
the part of the superior limb between the elbow and the wrist
"She stretched out her forearm to reach for the book on the top shelf without standing up."
The part of the arm between the wrist and the elbow.
"She stretched her forearm to relieve the tension after holding the baby for hours."
arm in advance of a confrontation
"He stepped forward to extend his forearm as an unspoken signal that he was ready for a fight but willing to de-escalate first."
To arm in preparation.
"The soldier raised his forearm to signal that he was ready to draw his weapon and engage the enemy."