Tights are a thin stretchy garment covering feet, legs and hips. A pair of tights, wear tights, ladder in her tights.
They are joined at the top where stockings are separate, which is the whole distinction. Americans call the sheer kind pantyhose and keep tights for the thicker sort. Denier measures the thread's weight, so a higher number means a thicker and more opaque garment.
1nountightsA thin stretchy garment covering feet, legs and hips.
“It was so cold that she wore thick woollen tights under her skirt.”
tights is clothing.
Proto-Indo-European
*tenkt- — dense, thick, tight
Proto-Germanic
*þinhtaz
Proto-West Germanic
*þį̄ht(ī)
Old English
*þiht
Middle English
tight
English
tight
English, today
tights
From tight + -s. tight comes from Middle English tight, tyght, tyȝt, tiht, variants of thight, thiht, from Old English þiht, þīht (attested in meteþiht), from Proto-West Germanic þį̄ht(ī), from Proto-Germanic þinhtaz, from Proto-Indo-European tenkt- (“dense, thick, tight”), from Proto-Indo-European ten- (“to stretch, pull”). Cognate with Scots ticht, West Frisian ticht, Danish tæt, Icelandic þéttur (“dense”), Norwegian tett, Swedish tät, Dutch dicht (“dense”), German dicht (“dense”). The current form with t- /t/ rather than etymologically-expected th- /θ/ arose in Middle English under the influence of the etymologically-unrelated verbs tighten and tight, which come from a different Proto-Indo-European root (starting with *d- and thus regularly having t-).
Etymology from Wiktionary, CC BY-SA