The story
- Proto-Indo-European*ḱe?
- Proto-Indo-European*ḱóm
- Proto-Italic*kom
- Old Latincom
- Latincum
- Proto-Indo-European*ḱerd-
- Proto-Indo-European*ḱḗr ~ *ḱr̥dés
- Proto-Italic*kord
- Latincor
- Latinconcors
- Latinconcordō
- Late Latinconcordantia
- Old Frenchconcordance
- Englishconcordance
- English todayconcordancer
From concordance + -er.
Etymology from Wiktionary, CC BY-SA 4.0.