What does fifthly mean?
Fifthly is a formal adverb used to introduce the fifth item in a sequence of points, reasons, or arguments. It belongs to the same family as firstly, secondly, thirdly, and fourthly, and serves as a signpost that helps readers and listeners follow an ordered line of reasoning. It appears most often in essays, speeches, official reports, and other structured prose where clarity of organisation matters. While perfectly correct, fifthly carries a somewhat formal, even old-fashioned tone; many contemporary style guides recommend using the plain ordinal 'fifth' instead, particularly in journalism and business writing. The word derives from 'fifth', the ordinal form of 'five', combined with the adverbial suffix '-ly'. Though rarely celebrated, fifthly exemplifies how English builds precise discourse markers to guide readers through complex argumentation step by step.
adverbFifthly is used to introduce the fifth item, point, or reason in a sequence or enumeration.
- Used to mark the fifth item or point in a numbered or ordered list of statements, reasons, or arguments.
"Fifthly, we must consider the environmental impact of the proposed development."
"Fifthly, the report recommends expanding staff training across all departments."
"The scheme has several merits: it saves money, reduces waste, improves safety, boosts morale and, fifthly, enhances the firm's public image."
Style guides have long quarrelled over 'firstly' — but 'fifthly' quietly does its job in enumerations without ever drawing that fire.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of fifthly
Fifthly is formed from the English ordinal numeral 'fifth' — which traces back through Old English 'fīfta' to the Germanic root underlying 'five' — plus the adverbial suffix '-ly'. The pattern of using '-ly'-marked ordinals (firstly, secondly, and so on) to enumerate points became established in English prose by around the early seventeenth century. The underlying numeral 'five' ultimately descends from Proto-Germanic '*fimf', cognate with Latin 'quinque' and Greek 'pente', which give English words such as quintet and quintuple.
Related word forms
How fifthly is actually used
Fifthly belongs chiefly to formal writing, especially structured arguments, essays, and official reports. Many modern style guides prefer simply 'fifth' (without -ly) when enumerating points, and some writers avoid the whole 'firstly/secondly/...' series altogether; nonetheless, fifthly remains grammatically standard and clearly understood.
Easily confused with fifthly
Fifty refers to the number 50, whereas fifthly introduces the fifth point in an enumeration.