" in chemistry it indicates a compound containing two units of the element or radical to which it is prefixed. the form di scienze is used after verb forms ending with a vowel ( namely the simple future tense), while ti is used after other verb forms which end in - t. detective inspector il libro di matematica e scienze pdf 3. copyright © harpercollins. donor insemination collins english dictionary. di is also the form used as an emphatic pronoun after dy ( “ your” ) in possessive pdf and infinitive contexts. defence intelligence 2. ( 1) word- forming element of greek origin meaning " two, libro double, twice, twofold, " from greek di-, shortened form of dis " twice, " which is related to duo " two" and matematica cognate with bi-, from pie root * dwo- " two. di in british english abbreviation for 1.