Protect, v. t. [imp. & p. p. Protected; p. pr. & vb. n. Protecting.]
Etymology: [L. protectus, p. p. of protegere, literally, to cover in front; pro before + tegere to cover. See Tegument.]
To cover or shield from danger or injury; to defend; to guard; to preserve in safety; as, a father protects his children. The gods of Greece protect you! Shak.
Syn. -- To guard; shield; preserve. See Defend.
Shades of meaning
Fernald has no entry of its own for protect; he lists it under cherish, keep, shelter.
Where he writes about it:
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. — from shelter
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. — from shelter
To defend (L. defendere, to strike away) implies the actual, protect (L. protegere, to cover before) implies the possible use of force or resisting power; guard implies sustained vigilance with readiness for conflict; we defend a person or thing against actual attack; we guard or protect against possible assault or injury. — from shelter
A powerful person may protect one who is weak by simply declaring himself his friend; he defends him by some form of active championship. — from shelter
An inanimate object may protect, as a garment from cold; defend is used but rarely, and by somewhat violent metaphor, in such connection. — from shelter
Protect is more complete than guard or defend; an object may be faithfully guarded or bravely defended in vain, but that which is protected is secure. — from shelter