“Long in the tooth” is an informal expression meaning old or getting old, sometimes with the implication of being too old for a particular activity. Cambridge supports the modern meaning and register; this guide does not turn the familiar horse-teeth explanation into a proved single-origin claim.
ReviewedEvidence1 sourceSectionPhrases & Idioms
Quick answer
If someone is “long in the tooth,” they are old or getting old, often humorously or critically in context.
Key details
Canonical Formlong in the tooth
Core Meaningold or getting old
Registerinformal
Further guidance
History Boundary
Current meaning is supported; exact coinage/origin chronology remains outside this guide.
Meaning
Cambridge defines the idiom as being old, often too old to do something.
Tone
Because the phrase comments on age, it can sound humorous, teasing, or unkind depending on context.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
A “breath of fresh air” describes someone or something that feels new and different and makes a situation more exciting. The guide stays with current documented meaning rather than unsupported origin chronology.
A “change of heart” means changing your opinion or feelings about something. The guide establishes the present-day idiom and does not invent an exact coinage or first-use account.
“A fish out of water” describes someone who feels awkward, uncomfortable, or out of place because the situation is unfamiliar or they do not fit the surrounding group.
“As cool as a cucumber” describes striking calmness or composure. The guide stays with the documented modern meaning and does not invent an exact inventor or first-use story.
“As fit as a fiddle” means very healthy and physically strong. The guide stays with documented present-day meaning and does not invent an exact origin or first-use story.
“As right as rain” means healthy or well again, often after illness or another temporary problem. The guide stays with documented present-day meaning and does not invent an exact origin or first-use story.
“Blow off steam” describes releasing pent-up feelings or energy through some action or expression. The guide publishes the current documented idiom without making unsupported claims about its exact origin.
Figuratively, “boiling point” is the stage at which anger or tension is close to becoming uncontrollable. The term also has a literal scientific meaning for the temperature at which a liquid boils; context determines whether the figurative or physical sense is intended.
