| An Obama | 8 |
| An oath on it was once held to be inviolable | 44 |
| An Oakley | 9 |
| An O.K. Corral gunfighter | 25 |
| An O.K. | 7 |
| An O'Neill play | 19 |
| An O'Neill | 14 |
| An O'Neal | 13 |
| An O may symbolize one | 22 |
| An NFL team is named for one of his works | 41 |
| An NFL team | 11 |
| An NFL rivalry | 14 |
| An NFL Manning | 14 |
| An NCO, informally | 18 |
| An NCO | 6 |
| An N.Y.C. subway | 16 |
| An N.L.-er | 10 |
| An N.F.L. player | 16 |
| An N.C.O. | 9 |
| An N.B.A. team | 14 |
| An MIT grad. | 12 |
| An MIT grad, perhaps | 20 |
| An MGM lion | 11 |
| An M.V.P.: 1980 | 15 |
| An M.V.P.: 1970, 1972 | 21 |
| An M.V.P.: 1954, 1965 | 21 |
| An M.V.P. in 1980 | 17 |
| An M.I.T. degree | 16 |
| An LBJ daughter | 15 |
| An L.B.J. dog | 13 |
| An L.B.J. daughter | 18 |
| An L.B.J. beagle | 16 |
| An L.A. eleven | 14 |
| An Ivy, briefly | 15 |
| An Ivy Leaguer | 14 |
| An Ivy League jewel? | 20 |
| An Ivy | 6 |
| An itemized deduction | 21 |
| An Italian sauce | 16 |
| An Italian dish | 15 |
| An Italian cuisine | 18 |
| An Italian cheese | 17 |
| An isolate | 10 |
| An Isaac Bickerstaff | 20 |
| An irritated state | 18 |
| An Iroquois | 11 |
| An Iroquoian map | 16 |
| An Iroquoian | 12 |
| An Irish Literary Theatre founder | 33 |
| An iris, for short | 18 |
| An iridaceous plant | 19 |
| An irid | 7 |
| An Iraqi | 8 |
| An Iranian religion | 19 |
| An Iranian language | 19 |
| An IRA may be part of it | 24 |
| An Iowa college | 15 |
| An Ionian island | 16 |
| An ion that migrates to the anode | 33 |
| An invitation might include one: Abbr. | 38 |
| An investment, perhaps | 22 |
| An Inverness is one | 19 |
| An inventor's monogram | 26 |
| An inventor's middle name | 29 |
| An inventor of the microphone | 29 |
| An invasion or hostile attack | 29 |
| An intriguing yarn | 18 |
| An Internet provider | 20 |
| An Internet address ender | 25 |
| An international society member | 31 |
| An intermission follower | 24 |
| An interest of T.A.E. | 21 |
| An interest of NOW | 18 |
| An intense emotion | 18 |
| An intelligence agent ___ | 25 |
| An integral can compute it | 26 |
| An intangible air | 17 |
| An insurance policy may not cover it | 36 |
| An instruction impossible to fulfill | 36 |
| An instant | 10 |
| An inspiring intro? | 19 |
| An inspiration to Beethoven | 27 |
| An Inspector Calls playwright | 32 |
| An inset might depict one | 25 |
| An insecticide, for short | 25 |
| An insecticide | 14 |
| An insect and a musical group are in his name | 45 |
| An inro may be attached to it | 29 |
| An inning's three? | 22 |
| An inning has six | 17 |
| An inlet | 8 |
| An inland sea | 13 |
| An initial, e.g. | 16 |
| An Ingmar protégée | 24 |
| An infusion | 11 |
| An inflorescence | 16 |
| An inferred conclusion | 22 |
| An inert gas | 12 |
| An inedible raspberry | 21 |
| An inedible orange | 18 |