Difference between old, elderly, aged and mature

Today’s English
March 6th, 2017

There seems to be no definite age to use as a point of reference to call someone to be old.  The term “old" is however used in three situations : while comparing one with another, to refer to a person officially who is over 58 or 60 and to refer to a person who is not able to do something(?) because of their aged conditions.

1.She is older than me and I can’t marry her.
2.I’m old enough now to claim the concessions for senior citizens.
3.I’m too old to apply for this job. (=Not eligible to apply for...)

When you say “elderly” or “senior"  instead of “old", you respect their age, experience and skills.

1.Thanks to our lucky stars. We have senior English faculty members in our group.
2.I feel happy to work with elderly people.

When you use “aged", it means “very old"
1.Please move to some other seat sir. It’s meant for aged people.
2. Aged people generally book lower birth, don’t they?

When you use the term “mature",  you mean that someone is “fully grown" or “no longer young".

1.She is not mature enough to get married now. (Not fully grown, especially mentally)
2.This shop sells apparel meant for mature woman. (Politely mentioning those women who are no longer young).

Here we are reminded of how Shakespeare has described the old age of man, especially in the sixth and seventh stage of Life:

"The sixth age shifts
Into the lean and slipper'd pantaloon,
With spectacles on nose and pouch on side,
His youthful hose, well saved, a world too wide
For his shrunk shank; and his big manly voice,
Turning again toward childish treble, pipes
And whistles in his sound. Last scene of all,
That ends this strange eventful history,
Is second childishness and mere oblivion,
Sans teeth, sans eyes, sans taste, sans everything.”
-By Jaques in As You Like It