cacher

from Latin coacto (to constrain) which gave the frequentative coacticare ('to compress, squeeze') in Late Latin and quachier, cachier in Old French. The Old French escachier still has the meaning of 'to crush'; the meaning of 'to conceal', rare until the sixteenth century, is derived from that of 'to press, compress'; this verb eventually supplanted in this sense the old verbs escondre, esconser, puter, and musser.