Entry 1 sense Webster, 1913 Subclavian · Sub·cla·vi·an · IPA /səbˈkleɪ.vi.ən/ 01 a. Situated under the clavicle, or collar bone; as, the subclavian arteries. 1. Situated under the clavicle, or collar bone; as, the subclavian arteries.(Anat.)