Parlous

1. (a.) Attended with peril; dangerous; as, a parlous cough.

2. (a.) Venturesome; bold; mischievous; keen.

Thesaurus Entries

alarming, awkward, bad, chancy, critical, dangerous, dangersome, difficult, explosive, fraught with danger, hairy, hazardous, iffy, jeopardous, menacing, periculous, perilous, precarious, risky, serious, threatening, ticklish, ugly, uncertain