(optics) a positive-powered lens or group of lenses that comes after the objective lens and before the image plane or the eyepiece, serving to change the size of the image

An athletics discipline that takes place on the field, such as hammer, javelin, triple jump

Field's metal

A fusible eutectic alloy of bismuth, indium, and tin.

(mathematics) A field that is also a topological space in which addition and multiplication are both continuous.

(algebra) A field all of whose elements can be represented as ordered pairs each of whose components belong to a given integral domain, such that the second component is non-zero, and so that the additive operator is defined like so: (a,b)+(a',b')=(ab'+a'b,bb'), the multiplicative operator is defined coordinate-wise, the zero is (0,1), the unity is (1,1), the additive inverse of (a,b) is (-a,b), equivalence is defined like so: (a,b)≡(a',b') if and only if ab'=a'b, and multiplicative inverse of a non-zero–equivalent element (a,b) is (b,a).

An engineer who works at an oilfield

plural of field gun

plural of field guide

A contest between gun dogs / A practical test, especially one conducted in the wild