What is referred to by 'circum'?

Based on the clue 'circles thermometers college grads are marked by ...', what is the answer? Based on the clue 'circuit riding preachers of pioneer days were most...', what is the answer? Based on the clue 'circular foliage arrangement used for ornamental p...', what is the answer? Based on the clue 'circular spinning food tray on a table set for a s...', what is the answer? What is referred to by 'circumstance partner for elgar'? Based on the clue 'circus folk call this animal a convict no offense ...', what is the answer? What is associated with: circus oz which turned 21 in 1999 is a zany satirical circus from this country thats nicknamed… Based on the clue 'circus polka was originally choreographed for thes...', what is the answer?