Senior vs. Sir — What's the Difference?

Of or for older or more experienced people

Sir is a formal English honourific address for men, derived from Sire in the High Middle Ages. Traditionally, as governed by law and custom, "Sir" is used for men titled as knights, i.e., of orders of chivalry, and later also applied to baronets and other offices.

High or higher in rank or status

Sir Used as an honorific before the given name or the full name of baronets and knights.

A person who is a specified number of years older than someone else

Used as a form of polite address for a man

Abbr. Sr. Of or being the older of two, especially the older of two persons having the same name, as father and son.

Used as a salutation in a letter

Of or relating to senior citizens.

A man of a higher rank or position.

Being in a position, rank, or grade above others of the same set or class

A respectful term of address to a man of higher rank or position, particularly:

Having precedence in making certain decisions.

To a knight or other low member of the peerage.

Of or relating to the fourth and last year of high school or college

To a superior military officer.

Relating to or being a class of corporate debt that has priority with respect to interest and principal over other classes of debt and equity by the same issuer.

To a teacher.

A person who is older than another

A respectful term of address to an adult male (often older), especially if his name or proper title is unknown.

A senior citizen.

To address (someone) using "sir".

One that is of a higher position, rank, or grade than another in the same set or class.

A man of social authority and dignity; a lord; a master; a gentleman; - in this sense usually spelled sire.

A student in the fourth year of high school or college.

A title prefixed to the Christian name of a knight or a baronet.

Older; superior

An English rendering of the LAtin Dominus, the academical title of a bachelor of arts; - formerly colloquially, and sometimes contemptuously, applied to the clergy.

Higher in rank, dignity, or office.

A respectful title, used in addressing a man, without being prefixed to his name; - used especially in speaking to elders or superiors; sometimes, also, used in the way of emphatic formality.

(US) Of or pertaining to a student's final academic year at a high school (twelfth grade) or university.

Term of address for a man

An old person.

A title used before the name of knight or baronet

Someone older than someone else (with possessive).

Someone seen as deserving respect or reverence because of their age.

An elder or presbyter in the early Church.

Somebody who is higher in rank, dignity, or office.

A final-year student at a high school or university.

More advanced than another in age; prior in age; elder; hence, more advanced in dignity, rank, or office; superior; as, senior member; senior counsel.

Belonging to the final year of the regular course in American colleges, or in professional schools.

A person who is older than another; one more advanced in life.

One older in office, or whose entrance upon office was anterior to that of another; one prior in grade.

An aged person; an older.

One in the fourth or final year of his collegiate course at an American college; - originally called senior sophister; also, one in the last year of the course at a professional schools or at a seminary.

An undergraduate student during the year preceding graduation

A person who is older than you are

Older; higher in rank; longer in length of tenure or service;

Used of the fourth and final year in United States high school or college;

Advanced in years; (`aged' is pronounced as two syllables);