a field lens is
41Magnetic field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
42To back against the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
43To back the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
44To bet on the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
45To keep the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
46To lay against the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
47To take the field — Field Field (f[=e]ld), n. [OE. feld, fild, AS. feld; akin to D. veld, G. feld, Sw. f[ a]lt, Dan. felt, Icel. fold field of grass, AS. folde earth, land, ground, OS. folda.] 1. Cleared land; land suitable for tillage or pasture; cultivated ground; …
48Lens — The transparent structure inside the eye that focuses light rays onto the retina (the nerve layer that lines the back of the eye, senses light and creates impulses that go through the optic nerve to the brain). The lens was named after the lentil …
49field — /feeld/, n. 1. an expanse of open or cleared ground, esp. a piece of land suitable or used for pasture or tillage. 2. Sports. a. a piece of ground devoted to sports or contests; playing field. b. (in betting) all the contestants or numbers that… …
50field — [[t]fild[/t]] n. 1) agr. a piece of open or cleared land, esp. one suitable for pasture or tillage 2) spo a) a piece of ground devoted to sports or contests; playing field b) an area in which field events are held 3) a sphere or branch of… …