Open English Wordnet
Verbs
(v)study, meditate, contemplatethink intently and at length, as for spiritual purposes“He is meditating in his study”
(v)chew over, think over, meditate, ponder, excogitate, contemplate, muse, reflect, mull, mull over, ruminate, speculatereflect deeply on a subject“I mulled over the events of the afternoon”, “philosophers have speculated on the question of God for thousands of years”, “The scientist must stop to observe and start to excogitate”