1540s, from French calamiteux (16c.), from Latin calamitosus "causing reduction, destructive," from calamitas (see disaster). Relevant: Calamitously; calamitousness.
(of events) having extremely regrettable or dire consequences; bringing spoil
- putting up with disaster; wretched; unhappy.
- yielding, or went to with distress and distress; making wretched; wretched; unhappy.
A calamitous atmospheric feature is the periodical arrival of storms called typhoons (Japanese tai-fu or great wind).