Solution

SHIELDS

4 clues

Defends

Word class: Verb
Nature of clue: Synonym
Difficulty: Easy
Sources: Boatload Puzzles

Guards

Word class: Verb
Nature of clue: Synonym
Difficulty: Easy
Sources: Boatload Puzzles

Other solutions to Guards

Knight protectors

Word class: Common noun
Nature of clue: Description
Difficulty: Easy
Sources: Boatload Puzzles
Topics: History
From which decade: Older times

Protects

Word class: Verb
Nature of clue: Synonym
Difficulty: Easy
Sources: Boatload Puzzles

Other solutions to Protects

Words are categorized by artificial intelligence: there can be mistakes.