grinding >> ˈɡrʌɪndɪŋ
Definition: [adjective] (of a difficult situation) oppressive and seemingly without end.
Example: grinding poverty
Definition: [adjective] (of a sound or movement) harsh and grating.
Example: the grinding roar of the lorries
Definition: [noun] the reduction of something to small particles or powder by crushing it.
Example: the roasting and grinding of grain, usually barley, for use in brewing
Definition: [noun] the action of rubbing things together gratingly.
Example: it's a question that has caused much grinding of teeth among scientists and medics over the last 50 years