Here is a list of Spanish words that start with tri:
triaca, triacal, triache, trianera, trianero, triangulada, triangulado, triangular, triangularmente, triaquera, triaquero, triar, triario, tribal, tribaquio, triboco, tribraquio, tribu, tribual, tribuente, tribuir, tribulante, tribulanza, tribular, tribuna, tribunado, tribunal, tribunato, tribunicia, tribunicio.
tribuno, tributable, tributante, tributar, tributaria, tributario, tributo, tricahue, tricenal, tricentenario, triciclo, triclinio, tricloruro, tricolor, tricorne, tricornio, tridacio, tridente, tridentina, tridentino, triduana, triduano, triduo, triedro, trienal, trienio, triente, triestina, triestino, trifauce, trifinio, triflora, trifloro, trifoliada, trifoliado, trifolio, triforio, triforme, trifulca, trifurcada, trifurcado, trifurcar, trifurcarse, triga, trigal.
trigaza, trigla, triglifo, trigo, triguera, triguero, triguillo, trile, trilita, trilito, trilla, trillada, trilladera, trillado, trillador, trilladora, trilladura, trillar, trillique, trillo, trilobites, trilobulada, trilobulado, trilocular, trimembre, trimestral, trimestralmente, trimestre, trimielga, trimotor, trimurti, trina, trinacria, trinacrio, trinado, trinante, trinar, trinca, trincadura, trincaesquinas, trincar, trincha, trinchador, trinchadora, trinchante, trinchar.
trinche, trinchea, trinchear, trincheo, trinchera, trinchero, trinchete, trineo, trinidad, trinitaria, trinitario, trinitrotolueno, trino, trinomio, trinquetada, trinquete, trinquete4, trinquetilla, trinquis, triodo, triones, tripa, tripada, tripartir, tripartita, tripartito, tripastos, tripe, tripera, tripero, tripicallera, tripicallero, tripicallos.
tripla, triplano, triple, triplicar, triplicidad, triplo, tripolina, tripolino, tripolitana, tripolitano, tripona, tripote, triptico, triptongar, triptongo, tripuda, tripudiante, tripudiar, tripudio, tripudo, tripulante, tripular, trique, triquete, triquina, triquinosis, triquitraque, trirreme, tris, trisa, trisagio.
trisar, trisca, triscador, triscadora, triscar, trisecar, trisemanal, trismo, trispasto, triste, tristemente, tristeza, tristona, tristor, tristura, trisulca, trisulco, triturable, triturador, trituradora, triturar, triunfador, triunfadora, triunfal, triunfalmente, triunfante, triunfantemente, triunfar, triunfo, triunvirado, triunviral, triunvirato, triunviro, trivial, trivialidad, trivialmente, trivio, triza, trizar,
Hope this list of Spanish words that start with tri was helpful. In addition to the Spanish words that begin with tri found on this page, this site contains many other lists of Spanish vocabulary words starting with various letters which may be useful for learning the language.