"given to speaking freely, candid, free or bold of speech," 1808, originally Scottish, from out- + -spoken. According to OED, the past participle "has here a resultant force, as in 'well spoken', 'well read'." Related: Outspokenly; outspokenness. Earlier was outspeaking, in reference to the voice, "loud, resonant" (mid-15c.).
outspoken in their opposition to segregation
it is possible to be outspoken without being rude
outsized
outskirt
outsmart
outsource
outspend
outspoken
outspread
outstanding
outstay
outstretch
outstrip