Webster's Revised Unabridged Dictionary · 1913

Estimate

Estimate , transitive verb

[Latin aestimatus, past participle of aestimare. See Esteem, transitive verb]

1.
To judge and form an opinion of the value of, from imperfect data, -- either the extrinsic (money), or intrinsic (moral), value; to fix the worth of roughly or in a general way; as, to estimate the value of goods or land; to estimate the worth or talents of a person.
It is by the weight of silver, and not the name of the piece, that men estimate commodities and exchange them. — Locke
It is always very difficult to estimate the age in which you are living. — J. C. Shairp
2.
To from an opinion of, as to amount,, number, etc., from imperfect data, comparison, or experience; to make an estimate of; to calculate roughly; to rate; as, to estimate the cost of a trip, the number of feet in a piece of land.

Estimate , noun

A valuing or rating by the mind, without actually measuring, weighing, or the like; rough or approximate calculation; as, an estimate of the cost of a building, or of the quantity of water in a pond.
Weigh success in a moral balance, and our whole estimate is changed. — J. C. Shairp
No; dear as freedom is, and in my heart's Just estimation prized above all price. — Cowper