ac·ces·so·ry (k-ss-r) KEY
Middle English accessorie, from Medieval Latin accessrius, from accessor, helper, from Latin accessus, approach ; see access
acces·sori·al (-s-sôr-l, -sr-) KEY (Adjective), ac·cesso·ri·ly(Adverb), ac·cesso·ri·ness(Noun)
Although the pronunciation (-ss-r), with no (k) sound in the first syllable, is commonly heard, it is not accepted by a majority of the Usage Panel. In a recent survey, 87 percent of the Panelists disapproved of it. The 13 percent that accepted the pronunciation were divided on usage: more than half accepted the (k)-less pronunciation for all senses. A few approved of it only in fashion contexts, and a few others approved of it only in legal contexts.