aperture; bore; calibre; caliber
path; lane; small diameter; small radius
course; route; path; process; means
impulsive and straightforward; guileless
small calibre; small caliber
radius of action; sphere of activity
groin; groin region; inguinal region
road; path; route; way; distance; journey; road (e.g. to victory)
grain diameter; particle diameter
semi-major axis (esp. in orbital matters)
distance between two points; distance between opposite supports of arch, bridge; span
groin; groin region; inguinal region
core diameter (of a fiber)
conjugate diameter pair; CDP
aperture ratio (inverse of the f-number); relative aperture
semi-minor axis (esp. in orbital matters)
particle size; particle diameter
lymphogranuloma venereum; lymphogranuloma inguinale