prije, pensycertu
tsajmi 'strong understand', as opposed to 'weak-understand' rubjmi ("stupid"). prije means 'wise' as opposed to bebna 'foolish'. And pensi 'think about' is closer to "contemplate" than some process of ratiocination. "Analyze" might be conveyed by ckiski 'explainingly-describe'. But Lojbanic psychology is still in its infancy...
banzu jinvi
When I say "intelligent", I often mean menstati, "mentally talented". mi'e jezrax