What does thirdly mean?
Thirdly is an adverb used to introduce the third point in a sequence, discussion, or argument. It commonly occurs in coordinated constructions such as “firstly, secondly and thirdly,” helping the listener or reader follow the development of an argument. The word is especially associated with formal speeches, academic prose, presentations, and structured explanations, although it is also used in ordinary conversation when someone is deliberately listing several points. It is not merely a less formal alternative to “third”: “thirdly” specifically signals an item's position in an ordered series. Its use can make a discussion sound organized and persuasive, but in informal settings it may sound somewhat formal or old-fashioned. Related expressions such as “firstly” and “secondly” perform the same enumerative function at earlier positions, while “lastly” and “finally” conclude a sequence. Thirdly is therefore useful whenever a speaker wants to make the progression of points unmistakable.
adverbUsed to introduce the third point, reason, or item in a sequence or argument.
- As an enumerative adverb, thirdly introduces the third point, reason, or item in a sequence or argument.
"Thirdly, the proposed changes would reduce costs while protecting the existing service."
"Thirdly, the evidence shows that the policy would benefit smaller communities."
"The speaker explained the issue firstly, secondly and thirdly, concluding with a call for reform."
Thirdly is the small linguistic signal that an argument has reached its third—and often decisive—turn.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thirdly come from?
Thirdly was formed in English by adding the adverb-forming suffix -ly to third. Third comes from Old English þridda, the ordinal numeral associated with three, and ultimately reflects a Germanic numeral tradition. The same numeral family also underlies three and thrice, while threefold is a later English compound based on three. The suffix -ly, originally associated with adjectives, became widely productive in forming adverbs from ordinal and descriptive words.
How thirdly is actually used
Thirdly is formal and enumerative, especially common in speeches, academic writing, presentations, and legal or argumentative prose. In everyday conversation, alternatives such as also, next, or finally may sound less ceremonious.
Easily confused with thirdly
Thirdly is an adverb that introduces the third point in a sequence, whereas third is primarily an ordinal adjective or noun.