also: じゅうか
heavy load; heavy burden; heavy freight
Concrete use for something physically heavy that is carried, borne, or transported. The reading おもに is the ordinary one; じゅうか is much less common and sounds more technical or freight-related.
The horse went along the mountain path carrying a heavy load.
heavy responsibility; mental burden; encumbrance
Only with reading おもに
Figurative use for a responsibility, obligation, worry, or relationship that feels emotionally or practically oppressive. Common in patterns such as 重荷になる and 重荷を背負う.
The responsibility of supporting his family was a heavy burden for him.
That promise had become a burden to her.
The monthly loan payments have become a burden.
He carries the heavy burden of supporting his family.
Now that the project is over, I could finally set down the burden.
Her one remark lightened my burden.
責任 simply means responsibility, whereas 重荷 describes that responsibility once it is felt as an oppressive weight.
重責 is a formal term for a heavy official duty or post, while 重荷 is broader and can describe any emotionally oppressive burden.
重荷 is the everyday word for a heavy load or burden, both physical and emotional, while 荷重 is a more technical or literary term for the same idea.
重荷 is a more literary or emotional word for a heavy burden (often figurative), while 負荷 is used in technical or clinical contexts.
Standard and common reading, used for both literal heavy loads and figurative burdens.
Less common on-yomi reading, most plausible in literal or freight-related contexts rather than everyday figurative use.
A transparent compound of 重い／重, meaning heavy, and 荷, meaning load or baggage. The common reading おもに reflects a native-style reading, while じゅうか is an on-yomi reading.