sirji -sir- gismu

x1 is straight/direct/line segment/interval between x2 and x3; (adjective:) x1 is linear.

See also korcu, linji, kruvi, kuspe.


In notes:

korcu
(adjective:) x1 is bent/crooked/not straight or direct/[twisted]/folded.
kruvi
x1 is a curve/turn/bend in x2, at locus x3, and defined by set of points/properties x4.
kuspe
x1 ranges/extends/spans/persists/reaches across/over interval/gap/area/scope/extent/range x2.
linji
x1 is a line/among lines [1-dimensional shape/form] defined by set of points x2.
mijdi'esirji
x1 is a radius of shape x2
danci
x1 is the spacial interval/geodesic segment (or line segment/ray/line) from location/point x2 to location/point x3 in geometry/frame of reference x4.