v.
Pronunciation: ' här-d ə n
Function: verb
Inflected Form: hard · ened ; hard · en · ing \ ' härd-ni ŋ , ' här-d ə n-i ŋ \
Date: 13th century
transitive verb
1 : to make hard or harder
2 : to confirm in disposition, feelings, or action especially : to make callous < harden ed his heart>
3 a : INURE , TOUGHEN < harden troops> b : to inure to unfavorable environmental conditions (as cold) ― often used with off < harden off seedlings before transplanting>
4 : to protect from blast, heat, or radiation (as by a thick barrier or placement underground)
intransitive verb
1 : to become hard or harder
2 a : to become firm, stable, or settled b : to assume an appearance of harshness or severity <her face harden ed at the thought>
3 : to become gradually acclimatized to unfavorable conditions ― often used with off <plants harden ed off before the first frost>