Solitary; single, unmarried.

Consisting of only one part, element, or unit; single; = onefold, adj. 1. Now rare (Scottish and Irish English (northern) after Middle English).

Without companions or companionship, alone; solitary; lonely. In later use chiefly English regional (northern). Obsolete.

Unique, singular. rare.

One and only. Singular, unique, unrivalled.

Chiefly modifying an agent noun or its equivalent: sole, only. Obsolete.

Sole, unique.

Single, sole; alone, solitary; only. Cf. allenarly, adj.

attributive. One and only; singular. = only, adj. 2a. Obsolete.

Only, sole. Obsolete.

Forming the only one of the kind; unique, solitary, single. Also (with the), sole, only.

Chiefly poetic. Without peer, equal, or parallel; matchless; unique.

(un-, prefix1 affix 3.)

Of which there is only one; single, sole, solitary.

Only, sole. Obsolete.

Forming or consisting of one only; alone of its kind, unique.

Standing alone in comparison with other persons or things; unique, singular.

Standing alone or by itself; not accompanied or paralleled in any way.

Employed or followed to the exclusion of everything else; single, sole.

Made or done as the only one of its kind; unique, not repeated.

one-of-a-kind: (a) unique; (b) of only one kind (rare).