v.
(regrets, regretting, regretted)
feel or express sorrow, repentance, or disappointment over.
n.
a feeling of sorrow, repentance, or disappointment.
▸used in polite formulas to express apology or sadness.
Etymology
ME: from OFr. regreter ‘bewail the dead’, perh. from the Gmc base of greet2.