1. Open and observable; not hidden, concealed, or secret: overt hostility; overt intelligence gathering.2. Of, relating to, or being military or intelligence operations sanctioned or mandated by Congress: overt aid to the rebels.
ETYMOLOGY:
Middle English, from Old French, past participle of ovrir, to open, from Vulgar Latin *perre, alteration (influenced by Latin cperre, to cover) of Latin aperre; see wer-4 in Appendix I.