重たい|おもたいomotai[0]heiban (flat)

1. i-adjectiveheavy; weighty
   その箱ばこは重おもたくて運はこべません。↗

   The box is too heavy to carry.
2. i-adjectiveheavy (feeling, atmosphere, etc.); serious; gloomy; depressing

• Synonym重いおもいNeutralThe standard, most common word for 'heavy'; 「重たい」 is the more colloquial choice, stressing the heaviness you actually feel in your hands or heart.
• SynonymヘビーCasualColloquial loanword for something heavy, burdensome or intense, as in 「ヘビーな内容」「ヘビーユーザー」; leans toward degree of intensity rather than felt weight.
• Synonym重苦しいおもくるしいNeutralMostly for a gloomy, oppressive mood or atmosphere, as in 「重苦しい空気」; for clothes and gear it stresses being weighed down, while 「重たい」 stresses felt weight in the hand.
• RelatedきついCasualColloquial for tough, tight or demanding, as in 「仕事がきつい」; it is about a heavy burden, not physical weight.
• RelatedしんどいCasualColloquial; originally a western-Japan dialect, now in wide use. Means tiring or exhausting, as in 「しんどい仕事」; about fatigue, not weight.
• RelatedハードCasualColloquial loanword for hard or high-intensity, as in 「ハードな練習」; it stresses intensity and is not used for the weight of objects.
• Related憂鬱ゆううつNeutralRefers to depression or a heavy heart, as in 「憂鬱な気分」; it is purely about one's mental state, not the weight of objects.
• Related陰気いんきNeutralDescribes a gloomy personality or atmosphere, as in 「陰気な人」; it carries a negative judgment and says nothing about weight.
• Antonym軽いかるいNeutralThe opposite of 「重たい」: light in weight, and by extension light in degree or severity.
• Antonym軽量けいりょうWrittenA written/formal word for light weight, mostly in product specifications; the counterpart of 「重たい」.

Use 「重たい」 in speech when you want to stress heaviness felt in the hands or heart; for the general 'heavy' say 「重い」. For an oppressive atmosphere use 「重苦しい」, for hardship 「きつい」; the opposite is 「軽い」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （場合ばあいによっては口語こうご的てき）重おもい。重おもさを感かんじさせる。重おもくて苦くるしい。