noun
: a linkage through hydrogen of two electronegative atoms especially fluorine, oxygen, or nitrogen with one side of the linkage usually being a conventional covalent bond (as the −O−H bond in water H−O−H or alcohol R−O−H) and the other side being primarily electrostatic in character
the stable hydrogen fluoride ion HF 2 - or [F - H + F - ] - is held together by a hydrogen bond
— see association 7