Generally not gradable; comparative and superlative forms are archaic or non-standard.
Translations
The chief reason for the delay was the weather.
Главной причиной задержки была погода.
The chief concern of the committee is safety.
Основной заботой комитета является безопасность.
Definitions
The chief reason for the meeting was to discuss the budget.
Slang usage meaning ‘to smoke (especially marijuana)’; chiefly North American.
Definitions
Slang: to smoke (a cigar, cigarette, or marijuana), often continuously or greedily. They were chiefing blunts on the porch all night.