IPA: /ˌʌn.kənˈtɛm.plə.tɪd/
KK: /ʌnˈkɒntɛmpleɪtɪd/
Not thought about or considered beforehand.
The decision was made in an uncontemplated manner, leading to unexpected consequences.
Uncontemplated → It is formed from "un-" (meaning not) and "contemplate" (from Latin "contemplari", meaning to observe or consider). The word "uncontemplated" means not having been observed or considered thoughtfully.
Think of 'not' ('un-') having 'observed' or 'considered' something ('contemplate'). This helps you remember that 'uncontemplated' refers to something that has not been thought about.