Hukukutu (hardness in English) zvinoreva kuti chinhu chakasimba zvokuti hachimarike zviri nyore. Diamond inozivikanwa nokuva nehukukutu zvokuti hakuna chimwe chinokwanisa kuimara. Nokudaro diamond inoshandoswa pama drill anoshandiswa kucheka dombo pasi pemugodhi. Kukukutara (be hard). Gukuta (dry skin) zvichireva ganda rakawoma. Gukuta izita remhuri. VaSwahili vanoti kukutaa (be hard, be dried off e.g. the ground dried by the sun) zvichireva kuwomarara. VaSwahili vanoti kukutika (be dry, dried off). Umbundu vanoti kukuta (v.s. dry) kureva kukukuta. Baila vanoti bukukutu (extreme hardness) vachireva hukukutu. Baila vanoti buzumo (hardness) vachireva kuwomarara. Herero vanoti ou-kukutu (n. hardness) kureva hukukutu. Mamwe mazwi: kukutisa (n. harden) kureva kukukuta. Hardness Guide (english)