旨(man zhi3, can zi2, taishan dzi55), imperial decree, is a respectable word even in modern Chinese. However, it is much less so in everyday Cantonese and Taishanese. For example, 奉旨(can fung6zi2, taishan fəŋ32dzi55), literally by imperial decree, is commonly used adverbially as always with a negative take-it-for-granted connotation: 

    佢奉旨冇耳听! [kui33 fəŋ32 dzi55 mɔu33 ŋi55 hiaŋ335] She never listen!

    -佢又迟啊咯.    [kui33 yiu32 tsi22 a33 lɔ33] He's late again.
    -奉旨!              [fəŋ32 dzi55] What else would you expect!

Another term 旨意, decree/order from the Emperor or respected senior members of one's family, is widely used in both Cantonese and Taishanese in the phrase 唔使旨意  meaning It will not happen! or Don't even think about it! (Literally no decree!).

Cantonese speakers may stop here, but the Taishanese carry it further. Perhaps edicts from Peking were written in ambiguous and hard to understand terms that 估旨 [gu55dzi55], literally guessing the imperial decree,  is a Taishanese word used to indicate a thought or assumption that turned out to be wrong:

    估旨佢会来! [gu55 dzi55 kui33 vɔi21 lɔi22]  I thought he would come (and he didn't)!

按旨估 [ɔn33dzi55gu55], literally to guess according to the decree, is a colloquial word for being casual and careless, with 乱旨估 [lɔn32dzi55gu55] the stronger version (乱=disorderly, arbitrary, or indiscriminately):

    -我乱旨估做 a 住哇.     Well, I did the best I could (I really didn't know what I was doing).
    -按旨估 la52!                Do as you please! I don't really care! Just get it done!

毋旨估[mu21dzi55gu55], or its contracted form 毋旨[mu21dzi55], is the equivalent of the English phrase could it be that (毋=not/without) to express surprise in a sentence:

    毋旨佢去 a 等墟? [mu21 dzi55 kui33 hui33 a33 aŋ55 hui215]  Could it be that he had gone to the market?

 So much for the Imperial Decree -- as the Cantonese would say 山高皇帝远 the mountain are high and the emperor is far away [san33 gɔu33 vɔŋ22 ai33 yɔn55]. Who cares?

Taishanese Literal Meaning Cantonese Mandarin English
奉旨[fəŋ32dzi55] by imperial decree 奉旨 理所当然地 in a taken-for-granted manner
估旨[gu55dzi55] guessing the imperial decree 以为 以为 I thought (wrongly) that ...
按/乱旨估[ɔn33/lɔn32 dzi55gu55] according to/disorderly-decree-guess 求其 草草 careless(ly), casual(ly), indiscriminate(ly)
毋旨(估)[mu21dzi55(gu55)] no-decree-(guess) 唔通 难道 Could it be that ......?