'Conceal' shares its root with 'hell,' 'helmet,' and 'apocalypse' — all from PIE *kel- (to hide).
From Old French 'conceler,' from Latin 'concēlāre' (to hide completely, to conceal), an intensive compound of 'con-' (together, completely, intensive) + 'cēlāre' (to hide, to keep secret). The PIE root is *ḱel- (to cover, conceal, save), one of the most semantically fertile roots in Indo-European. From *ḱel- come: 'hell' (the hidden realm, Old English hel), 'helmet' (a covering for the head), 'hull' (the husk or covering of a seed), 'hall' (an enclosed