Etymology: < Middle French rut, ruit, ruyt sexual excitement (c1160 in Old French as ruit ; > ruit n.), periodic sexual excitement in animals (second half of the 12th cent.), ultimately (with loss of the medial -g-) < post-classical Latin rugitus action of roaring (4th cent.) < classical Latin rūgīre to roar (probably < the same Indo-European base as ancient Greek ἐρεύγεσθαι) + -tus, suffix forming verbal nouns. Compare post-classical Latin rutum (1241 in a British source). Compare Spanish ruido (a1207 as †roido), Portuguese ruido (13th cent. as †rruido), both in sense ‘noise, clamour‘.With at or in (the) rut at Phrases 1 compare post-classical Latin in ruto (1241 in a British source), Middle French, French en rut (1562 or earlier).

Etymology: Origin uncertain. Probably < rut v.², and thus ultimately parallel to rit n.¹, which shows significant semantic overlap, although this could partly result from association of rit n.¹ with this word; compare also ruck n.⁴, and later rut n.⁵ It is also possible that the word could show a variant of route n.¹ with shortened stem vowel. The relationship between the α. and β. forms is unclear. N.E.D. (1910) suggests that the spelling rupt may favour an etymological connection with Middle French (chiefly Eastern) rupt , rut brook, stream (French regional (Lorraine) rupt ; variant of riu , ru , etc.: see note at river n.¹). However, the English form rupt is apparently only attested in an isolated instance in 1600, and the French noun differs significantly in meaning. The form may have arisen instead by learned association with classical Latin rupt- , past participial stem of rumpere to break (see rumpent n.).

Etymology: Probably the reflex of a borrowing < early Scandinavian (compare Norwegian regional (southern) rut din, roar, rumble, racket (also Norwegian (Nynorsk) ruta to make a loud noise)) < an ablaut variant (zero-grade) of the Germanic base of either rout v.¹ (with the sense compare rout v.²) or (following the loss of initial h- ) of Old English rēotan to weep, wail (see rout v.⁴). Compare earlier rout n.⁴ and later rote n.⁵

Etymology: Origin uncertain. Perhaps an extended use of rut n.³, after rout n.¹ 5.

Etymology: < rut v.² Compare earlier rit n.¹ and also rut n.² and discussion at that entry.

Etymology: < rut n.¹ Compare Middle French, French ruter, rutter to be in rut (first half of the 15th cent. in an isolated attestation), to mount or copulate with (a female) (c1570).

Etymology: Variant of rit v.¹ Compare later rut n.² and discussion at that entry.

Etymology: Apparently < an otherwise unattested variant of route n.¹ (compare forms at that entry). Compare earlier rutter n.²).

Etymology: < rut n.² Compare earlier rut v.²