Printed or displayed in bold typeface, or metaphorically describing something done in an obvious, shameless, or brazen way.
From 'boldface' (noun) plus the suffix '-ed,' creating an adjective. The metaphorical sense developed from the idea that bold text is impossible to miss or ignore, so a 'boldfaced lie' is one stated shamelessly.
The metaphorical use of 'boldfaced' is brilliant—a boldfaced lie is one so obvious and unapologetic that it's like someone printed it in huge dark letters right in front of your face!
Complete word intelligence in one call. Free tier — 50 lookups/day.