That which covers may also defend or protect; thus, troops interposed between some portion of their own army and the enemy are often called a covering party. To shelter is to cover so as to protect from injury or annoyance; as, the roof shelters from the storm; woods shelter from the heat.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

keep The cold weather may keep the plants from budding.
defend We should tell the children how to defend oneself.
shield The goddess gave the warrior a sword and a shield.
preserve Here are a few good rules on how to preserve food.
save The word processor will save you a lot of trouble.
guard The security guard went back on his normal patrol.

Popularity over time

Word	1850 → 2019	Trend
protect		rising
keep		rising
defend		steady
shield		steady
preserve		steady
save		rising

Use in printed books, per decade from 1850 to 2019.

By length

3 letters: aid¹, arm¹
4 letters: keep¹, save¹, tend¹, mask¹
5 letters: cover², guard¹, fence¹, shade¹
6 letters: screen¹, secure², defend², shield¹, foster², harbor²
7 letters: support², shelter², harbour²
8 letters: preserve², befriend², beshield
9 letters: vindicate³

The small number after each word is its number of syllables (cover² = 2 syllables).

In other languages

Français: protéger
Deutsch: begünstigen
Català: protegir