(n.) One who meddles; one who interferes or busies himself with things in which he has no concern; an officious person; a busybody.
Example Sentences:
(1) Whatever else Valérie Trierweiler has been portrayed as – vengeful harpy, ambitious meddler, undignified ex – she is also a woman who has had her heart broken.
(2) Charles has waited decades to become King, he doesn't have the prospect of a long reign and he is a meddler by nature.
(3) In short, the meddlers had simply delivered another stealth tax.
(4) He is a city-dweller, a Whitehall centralist, a natural meddler, an interventionist at home and abroad.
(5) People will be watching to see if the action taken is in line with what is thought to be his view … People are sceptical and suspicious, and they have a right to know if the king has taken an interest.” The cache will tell another story too: that far from being a hobbyist meddler, the prince has been engaged in systematic and extensive lobbying of ministers.
(6) Even political opponents have supported Mr Livingstone against the adjudication panel, widely regarded as meddlers in the democratic process.
Muddler
Definition:
(n.) One who, or that which, muddles.
Example Sentences:
(1) Blood pressure was assessed by the random zero muddler method by trained nurses at screenings between March 1981 and August 1982; 47 men who received pharmacologic treatment for previously diagnosed hypertension were excluded from the analyses.
(2) The performance of the Copal Digital Sphygmomanometer UA251, a new semi-automatic blood pressure recorder, was evaluated by comparing the results obtained simultaneously and on the same arm using the standard zero-muddler sphygmomanometer.