As the first in a number of examples or reasons. / As a single given example, often the most obvious or important one and almost certainly enough to sway the argument, of several reasons for something.

simple past tense and past participle of one

plural of oneness

(uncountable) State of being one or undivided; unity. / (countable) The product of being one or undivided.

(Singapore, Philippines, Malaysia, transitive, colloquial); Third-person singular simple present indicative form of on

Belonging to one.

a ketone / any similar compound containing a carbonyl functional group

Of a period of time, being particular. / Being a single, unspecified thing; a; any. / Sole, only. / Whole, entire. / In agreement. / The same. / Being a preeminent example.

To cause to become one; to gather into a single whole; to unite.

The number represented by the Arabic numeral 1; the numerical value equal to that cardinal number. / (number theory) The first positive number in the set of natural numbers.