out on a limb

out on a limb (alone and without help or support; ) — в шатком положении; в рискованном положении; в опасном положении; затруднительном положении; под угрозой, под ударом; без опоры и поддержки
1
go out/be on a limb (do something risky or unsupported by others, which leaves you in a difficult position; take a chance, take a risk) — рисковать, ставить себя под угрозу, под удар;
If a person tells you that you’re going out on a limb, they’re warning you that you’re going to do or say something dangerous or unpopular.

Example 1: He'd gone out on a limb (=taken a risk) to help us. (CIDI)
Example 2: He's going out on a limb in criticizing his own party leadership. (CALD)
Example 3: I’d rather play it safe than go out on a limb.
Example 4: I don't think saying you support gay rights means you're going out on a limb these days.
Example 5: She is way out on a limb, tempting fate.
Example 6: "Tell me,” he asked her, eyebrows raised over her hand, "Are you the kind of woman who likes to live as far out on a limb as I do?" She glanced down at herself and laughed. "Looks that way to me."

2
go out on a limb (have an opinion that is different from most people's and is unpopular; hazard a wild guess; say something dangerous or unpopular) — (осмелиться/рискнуть) высказать непопулярное мнение, предположение;
If you go out on a limb, you state an opinion which is very different to most other people
Used in a more casual way, meaning that a person is making a guess about something that might seem a little crazy.

Example 1: Going out on a limb here… — Осмелюсь высказать предположение...; рискну высказать свое мнение на этот счет...; рискую остаться в одиночестве (высказывая непопулярное мнение); рискну показаться странным...
Example 2: I don't think we're going out on a limb in claiming that global warming is a problem that must be addressed.
Example 3: Rob Thompson, the producer, admits the series is going out on a limb in that it is quite different to anything else currently on television.

see also
[stick one's neck out]
To stick your neck out is to say or do something that is bold and a bit dangerous. A similar idiom that is used for slightly more dangerous situations is to go out on a limb. In both idioms, the idea is that you put yourself in a vulnerable position.

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Origin: Probably metaphorical, from the fact that if you're climbing a tree and you go too far out on a limb, you're taking a risk because the limb could break and you could fall to the ground and hurt yourself.