say it: SAHYD-lahyn
sideline is a noun and verb meaning "a line that marks the side boundary of a playing field". It carries 4 recorded senses.
a line that marks the side boundary of a playing field
an auxiliary line of merchandise
an auxiliary activity
remove from the center of activity or attention; place into an inferior position
“The outspoken cabinet member was sidelined by the President”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for sideline come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.