481. Impute, Assign

Assign: Allocate

482. Inane, Foolish

Inane: Silly
Foolish: Lacking sense

483. Incessant, Continuous

Incessant: Never stopping
Continuous: Unbroken

484. Incipient, Beginning

Incipient: In the early stage
Beginning: Starting

485. Incorrigible, Unmanageable

Incorrigible: Not correctable
Unmanageable: Hard to control

486. Indignant, Angry

Indignant: Feeling injustice
Angry: Feeling anger

487. Indispensable, Necessary

Indispensable: Absolutely required
Necessary: Needed

488. Indolent, Idle

Idle: Not active

489. Ineffable, Inexpressible

Inexpressible: Cannot be expressed

490. Inexorable, Unstoppable

Inexorable: Impossible to stop
Unstoppable: Cannot be halted

491. Infamous, Notorious

Infamous: Known for bad reasons
Notorious: Widely known negatively

492. Ingenious, Clever

Ingenious: Inventive
Clever: Smart