The small distortion of an astronomical instrument caused by the weight of its parts; the amount to be added or substracted from the observed readings of the instrument to correct them for this distortion
act of bending a joint; especially a joint between the bones of a limb so that the angle between them is decreased
an angular or rounded shape made by folding; "a fold in the napkin"; "a crease in his trousers"; "a plication on her blouse"; "a flexure of the colon"; "a bend of his elbow"