Rather = to some degree or quite, precisely, more truly, accurately.  It indicates an undesirable idea or connotation and viewed with disapproval.

EXAMPLES

• It’s rather a pity to imitate a drunkard.
• The burglary took place rather in the heart of the city.
• It’s rather hot today.
• She is rather fat.
• The task will take a good two years for accomplishment rather than months.

Note :  It gives stronger effect to the idea when followed by comparatives( stronger,  cheaper etc or by ‘too’.)  Mostly  this usage conveys undesirable ideas.  However , very rarely, it can be used in certain situations to convey desirable ideas also.  The following examples will clarify the usage.

• The shirt is rather too big for me.
• I am feeling rather better today.( desirable)
• He read the poem rather too quickly.
• The price was rather more than we could afford.
• The condition of the patient was rather better yesterday.(desirable)

A few more situations where ‘rather’ can be conveniently used.

(rather more expensive, rather stronger, rather too expensive,  rather too silly, rather too idiotic, rather surprising, rather tall, rather dark, rather strange, rather funny etc)