c. 1200, "a sentence, a brief passage of a written composition," from Old French clause "stipulation" (in a legal document), 12c., from Medieval Latin clausa "conclusion," used in the sense of classical Latin clausula "the end, a closing, termination," also "end of a sentence or a legal argument," from clausa, fem. noun from past participle of claudere "to close, to shut, to conclude" (see close (v.)).
Grammatical sense "one of the lesser sentences which united form a complex or compound sentence" is from c. 1300. Legal meaning "distinct condition, stipulation, or proviso" is recorded from late 14c. in English. The sense of "ending" mostly faded from the word between Latin and French, but it is occasionally found in Middle English.
A clause differs from a phrase in containing both a subject and its predicate, while a phrase is a group of two or more words not containing both these essential elements of a simple sentence. [Century Dictionary]
c. 1200, "person shut up or withdrawn from the world and secular living for purposes of religious meditation," originally and especially as a member of a religious community, from Old French reclus (fem. recluse) "hermit, recluse," also "confinement, prison; convent, monastery," noun use of reclus (adj.) "shut up," from Late Latin reclusus, past participle of recludere "to shut up, enclose" (but in classical Latin "to throw open"), from Latin re-, here perhaps an intensive prefix (see re-), + claudere "to shut" (see close (v.)).
Also in part via Medieval Latin nouns reclusus, reclusa. By late 17c. in the secular and softened sense of "one who lives a retired life and mixes little in society." Middle English also had a verb reclusen "to shut up (in some place), confine," and the past-participle adjective reclused "living in seclusion" (c. 1200). Recluse as an adjective meaning "shut up or apart from the world" is attested from early 13c. Also in Middle English was reclusion "state of retirement from the world" (c. 1400), from Medieval Latin reclusionem.