| Insulation ingredient | 21 |
| Insulation from jokes? | 22 |
| Insulation company | 18 |
| Insulation candidate | 20 |
| Insulation | 10 |
| Insulating tubing | 17 |
| Insulating silicate | 19 |
| Insulating material, for short | 30 |
| Insulating | 10 |
| Insulates, as a coat | 20 |
| Insulated space | 15 |
| Insulated sock | 14 |
| Insulated jacket | 16 |
| Insulated from worldly problems | 31 |
| Insulated electrical cable | 26 |
| Insulated cooler | 16 |
| Insulated container | 19 |
| Insulated coffee containers | 27 |
| Insulated chest | 15 |
| Insulate from change | 20 |
| Insulate a steam boiler | 23 |
| Insulate | 8 |
| Insular one | 11 |
| Insufficiently strict | 21 |
| Insufficiently filled, as a printed page | 40 |
| Insufficient, as one's best | 31 |
| Insufficient, as an excuse | 26 |
| Insufficient oxygenation of the blood | 37 |
| Insufficient older person? | 26 |
| Insufficient funds notification | 31 |
| Insufficient | 12 |
| Insufficiency | 13 |
| Insufferably confident | 22 |
| Insufferable, lovelorn and whiny, in slang | 42 |
| Insufferable type | 17 |
| Insufferable twit | 17 |
| Insufferable pair? | 18 |
| Insufferable ones | 17 |
| Insufferable one | 16 |
| Insufferable guests | 19 |
| Insubstantial stuff | 19 |
| Insubstantial amount | 20 |
| Insubstantial | 13 |
| Insubordination | 15 |
| Instumental Simon and Garfunkel jam | 35 |
| Insts. of learning | 18 |
| Insts. of higher learning | 25 |
| Insts. in Tex. and Mass. | 24 |
| Insts. for future executives | 28 |
| Instruments, for short | 22 |
| Instruments with trilling | 25 |
| Instruments with teakwood necks | 31 |
| Instruments with sympathetic strings | 36 |
| Instruments with stops | 22 |
| Instruments with slides | 23 |
| Instruments with pedals | 23 |
| Instruments with movable frets | 30 |
| Instruments with many strings | 29 |
| Instruments with many pedals | 28 |
| Instruments with low learning curves | 36 |
| Instruments with keys | 21 |
| Instruments with keyboards | 26 |
| Instruments with curved frets | 29 |
| Instruments with circular frames | 32 |
| Instruments used in orchestra tuning | 36 |
| Instruments used by the Beatles | 31 |
| Instruments used by the band Apocalyptica | 41 |
| Instruments tuned to "My Dog Has Fleas" | 49 |
| Instruments that usually have at least 18 strings | 49 |
| Instruments that often have chord buttons | 41 |
| Instruments that may be made from monkeypod wood | 48 |
| Instruments that literally mean "three flavor strings" | 64 |
| Instruments that are strummed | 29 |
| Instruments that are straddled when played | 42 |
| Instruments similar to English horns | 36 |
| Instruments setting | 19 |
| Instruments seldom seen in orchestras | 37 |
| Instruments playing false notes? | 32 |
| Instruments played with mizraabs | 32 |
| Instruments played with mallets | 31 |
| Instruments played with bows | 28 |
| Instruments played like rattles | 31 |
| Instruments played by Yusef Lateef and Sufjan Stevens | 53 |
| Instruments played at theaters during silent films | 50 |
| Instruments or plants | 21 |
| Instruments of yore | 19 |
| Instruments of war | 18 |
| Instruments of knowledge | 24 |
| Instruments of India | 20 |
| Instruments of destruction | 26 |
| Instruments in wind quintets | 28 |
| Instruments in the Beatles' "Norwegian Wood" and "Within You Without You" | 97 |
| Instruments in string quartets | 30 |
| Instruments in Ravel's "Boléro" | 48 |
| Instruments in pits | 19 |
| Instruments in military bands | 29 |
| Instruments in "The 5,000 Fingers of Dr. T" | 53 |
| Instruments heard at a luau | 27 |
| Instruments from Hawaii | 23 |
| Instruments for Yo-Yo Ma | 24 |