(idiomatic) To try or guess at something without having any knowledge about the subject.

Every decision has consequences; a person's actions will come back to them; if one starts trouble or takes actions in spite of the discontent they cause, one will incur negative consequences.

(idiomatic) alternative form of writing on the wall

(Britain, Ireland, colloquial) In an underhand way, sneakily; unofficially, particularly with regard to payment or tax avoidance.

Illicitly, against regulations, of goods kept under the serving counter in a shop to be unobtrusively passed to a customer who knows they are available for surreptitious sale (e.g. pornographic magazines in a newsagent).

(colloquial, with regard to income) Undeclared for tax and social insurance etc.

It appears; it seems; apparently.

(Ireland, historical) Electoral strategy pursued by the Irish Republican movement in the 1980s and early 1990s, where elections in Northern Ireland and the Republic of Ireland were contested by Sinn Féin, while the IRA continued military operations against the British Army and RUC.

(biblical) The fifth book in the New Testament of the Bible.

(idiomatic) The survival of the fittest, strongest, or most cunning