Indicating the last item. / Indicating the most important action. / (linguistics) Used to indicate the etymon at which a given etymological derivation terminates.

(obsolete) On the last day (of a specified month).

Of last month.

(obsolete, rare) = ultimum

Extremely conservative, especially in politics.

A person or group with extremely conservative views.

(acoustics) Beyond (higher in frequency than) the range of sound perceptible to the human ear; with a frequency of 20 kilohertz or higher.

of electromagnetic radiation beyond (higher in frequency than) light visible to the human eye; radiation with wavelengths from 380 nanometre - 10 nanometre

Ultraviolet colour.

(uncountable) Light in the ultraviolet part of the spectrum. / (countable) A light bulb that emits ultraviolet light; a black light.