seam, seem.
sear, sere, cere, seer.
serial, cereal.
signet, cygnet.
cist (box), cyst (tumour, Gr.).
scar (of wound), scar (a rock).
skull, scull.
scale (shell), scale (of balance), scale (of stairs).
scald (burn), skald (poet, Norse).
scrub (of shrubs), scrub (v.).