on

Multiple Entries:
  on    ON    -on  

Concise Oxford English Dictionary © 2008 Oxford University Press:
on/ɒn/

▶preposition

• 1 physically in contact with and supported by (a surface).

  ■ located somewhere in the general surface area of (a place).

  ■ on to.

  ■ in the possession of.

• 2 forming a distinctive or marked part of the surface of.

• 3 about; concerning.

  ■ having (something) as a basis.

• 4 as a member of (a committee, jury, etc.).

• 5 having (something) as a target, aim, or focus.

• 6 having (something) as a medium for transmitting or storing information.

  ■ being broadcast by (a radio or television channel).

• 7 in the course of (a journey).

  ■ while travelling in (a public service vehicle).

• 8 indicating the day or part of a day during which an event takes place.

  ■ at the time of.

• 9 engaged in.

• 10 regularly taking (a drug or medicine).

• 11 paid for by.

• 12 added to.

▶adverb

• 1 physically in contact with and supported by a surface.

  ■ (of clothing) being worn by a person.

• 2 indicating continuation of a movement or action.

  ■ further forward; in an advanced state.

• 3 (of an event) taking place or being presented.

  ■ due to take place as planned.

• 4 (of an electrical appliance or power supply) functioning.

• 5 (of an actor) on stage.

  ■ (of an employee) on duty.

▶noun (also on side) Cricket the leg side.

– phrases
be on about Brit. informal talk about tediously and at length.
be on at Brit. informal nag or grumble at.
be on to informal

• 1 be close to uncovering an illegal or undesirable activity engaged in by (someone).

• 2 (be on to something) have an idea that is likely to lead to an important discovery.

on and on continually; at tedious length.
on to moving to a location on the surface of (something) or aboard (a bus, train, etc.).

– origin OE on, an, of Gmc origin.

Concise Oxford English Dictionary © 2008 Oxford University Press:
ON1

▶abbreviation Ontario (in official postal use).

Concise Oxford English Dictionary © 2008 Oxford University Press:
ON2

▶abbreviation Old Norse.

Concise Oxford English Dictionary © 2008 Oxford University Press:
-on/ɒn/

▶suffix Physics, Biochemistry, & Chemistry forming nouns.

• 1 denoting subatomic particles or quanta: neutron.

• 2 denoting molecular units: codon.

• 3 denoting substances: interferon.

– origin Sense 1 orig. in electron, from ion, influenced (as in sense 2) by Gk on ‘being’; sense 3 is on the pattern of words such as cotton or from Ger. -on.