A single-stranded region at the end of a hairpin in RNA (or single-stranded DNA). It corresponds to the sequence between inverted repeats in duplex DNA.
A curve or bend in a line, especially one of the particular curves in a fingerprint.
A curved piece of wire placed in the uterus to prevent contraception.
A bend in a tubular organ, e.g. Henle’s loop in a kidney tubule.
A curve or bend in a cord or cordlike structure, forming roughly an oval.