Synonyms

[or indirect reference]

[irregularity]      

[severe/strict]

ASCETIC means practicing strict self-denial for moral or spiritual reasons. Option C 'given to self denial' directly matches this definition. Other options are unrelated: 'germ free' refers to hygiene, 'artistic' to creativity, and 'gloomy' to mood.

[spurious]

[express oneself]

ARABLE means land that is fit for or used for growing crops. Option A 'fit to plough' directly captures this agricultural meaning. 'Parched' means dry, 'easily crumbled' refers to texture, and 'likeable' refers to personality.

AMBIGUOUS means open to multiple interpretations or having unclear meaning. Option C 'obscure in meaning' directly corresponds to this definition. 'Skilful' and 'crafty' relate to ability/deception, while 'two fold' refers to quantity.

[to own/acknowledge frankly] to - one's loyalty

[to assign]

[to improve] to - conditions in slums

the - of life

behaviour

Audience means the act or state of hearing  

To talk negatively about someone when they're not present is called 'backbiting'. Option D 'Back bite' (though usually written as one word 'backbite') matches this definition. Other options are unrelated: 'Contagious' means spreading, 'Dowry' is property, and 'Illegal' means unlawful.