mark, 
blemish, stain, smudge, speck, dot 
pimple, 
pustule, boil, blackhead, whitehead, blocked pore, zit (slang) 
bit, 
soupçon, tad (informal), touch, smidgen (informal), dash 
place, 
location, site, setting, corner, situation, position, point 
advertisement, 
advert (UK, informal), ad, commercial, plug (informal), promotion 
predicament, 
mess, difficulty, awkward situation, quandary, plight