v.
Pronunciation: ' tha ŋ k
Function: transitive verb
Etymology: Middle English, from Old English thancian; akin to Old English thanc gratitude ― more at THANKS
Date: before 12th century
1 : to express gratitude to < thank ed her for the present> ― used in the phrase thank you usually without a subject to politely express gratitude < thank you for your consideration> or sometimes to emphasize a preceding statement especially by implying that it is not subject to question <likes her job just fine, thank you > ― used in such phrases as thank God, thank goodness usually without a subject to express gratitude or more often only the speaker's or writer's pleasure or satisfaction in something
2 : to hold responsible <had only himself to thank for his loss>
– thank · er noun