Vulnerable means easy to hurt, with nothing in the way to stop it. A newborn. A town with no wall, a boxer who has dropped his guard, a phone line left open all night.
It takes TO: vulnerable to attack, vulnerable to flooding, vulnerable to criticism. In law and social work it has hardened into a category — vulnerable adults, vulnerable children, vulnerable groups — meaning the people the system owes extra protection. Emotionally it has gone the other way and become something people choose: letting yourself be vulnerable, being vulnerable with a friend, saying the frightened thing out loud. In computing a vulnerable system has a hole in it, and the hole itself is a vulnerability. One thing to keep straight: vulnerable describes the one who can be wounded, never the thing doing the wounding.
1adjectivevulnerableEasy to harm, attack or hurt, with no defence in place.
“The camp was left vulnerable on the open side.”
synonyms: exposed, defenceless, unprotected
2adjectiveneedIn need of extra care and protection, in the language of law and social services.
“The scheme is aimed at vulnerable adults living alone.”
3adjectiveunguardedOpen about your feelings in a way that risks being hurt.
“It took him a year to be vulnerable enough to say it out loud.”
4adjectiveinsecureOf a system: open to attack because of a weakness in it.
“Any server still running that version is vulnerable.”
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: exposed
Vulnerable comes from Latin vulnerābilis, 'injurious, wounding', built on vulnerō, 'to wound', and behind that the Proto-Indo-European root *welh₃-. English kept the wound but turned it round: in Latin the word could mean able to wound, and in English it means able to be wounded.
Proto-Indo-European
*welh₃-
Latin
vulnerābilis — injurious, wounding
English, today
vulnerable
From Latin vulnerābilis (“injurious, wounding”), from Latin vulnerō (“to wound”).
Etymology from Wiktionary, CC BY-SA