cumbrous

Etymology

From Late Middle English combrous (“causing obstruction; clumsy; obstructed; bothersome, difficult; burdensome, onerous; serious; causing trouble, troublesome; dangerous; immoral; unjust, wrongful; upset”) [and other forms], from combren (“to annoy, harass, trouble, worry, vex; to conquer, defeat; to harm, ruin; to overcome, overwhelm, possess; (reflexive) to burden oneself, do wrong”) + -ous (suffix forming adjectives). Combren is possibly an aphetic form of acombren (“to annoy, harass, vex; to burden; to cause distress; to defeat, overwhelm; to bewilder, confuse, perplex; to tire; to upset”) (whence accumber (obsolete)) or encombren (“to annoy, trouble, vex; to assault, beset, harass; to block, hinder; to burden or be a burden; to choke; to defeat, overcome, overwhelm; to ensnare in sin, tempt to do wrong; to get stuck; to bewilder, confuse, perplex”) (whence encumber), though the Oxford English Dictionary notes that combren is first attested earlier than those words. If that derivation is correct, encombren is from Old French encombrer (“to annoy, bother, irritate; to burden”) (modern French encombrer), from Late Latin incombrāre, the present active infinitive of incombrō (“to burden; to hinder, inconvenience”), from Latin in- (prefix meaning ‘into, on, upon’) + combrus (“barrage, barricade; obstacle”), and combrus is either: * from cumulus (“a heap, pile”), ultimately from Proto-Indo-European *ḱewh₁- (“to swell”); or * ultimately from Proto-Celtic *kombereti (“to bring together”), from *kom- (prefix meaning ‘together; with’) + *bereti (“to bear, carry”) (from Proto-Indo-European *bʰéreti (“to be carrying”)). The English word is analysable as cumber + -ous.

adj

1. (also figurative) Unwieldy because of size or weight; cumbersome.
   This class of apparatus, often called today the "poste classique", gave first-class service in every respect but became cumbrous if a large layout had to be controlled. 1961 November, “The Development of ‘P.R.S.’ on the French Railways”, in Trains Illustrated, London: Ian Allan Publishing, →ISSN, →OCLC, page 664
   Evidently the imagines agentes, fantastically gesticulating from their places and arousing memory by their emotional appeal, seemed to him as cumbrous and useless for practical mnemonic purposes as they do to us. 1966, Frances A[melia] Yates, “The Art of Memory in Greece: Memory and the Soul”, in The Art of Memory, London: Pimlico, published 2007, page 41
2. (obsolete)
   1. Causing hindrance or obstruction.
   2. Giving annoyance or trouble; troublesome, vexatious.